Toddler Transition help

I’ll start out maybe with a little rant because I posted this question in a local mom fb group and someone commented that it must be autism. Now I have no issues with autism and would do anything that’s good & right for my child BUT he has zero other symptoms and to me this is something a lot of toddlers struggle with?? Or am I totally wrong? It just feels like everything nowadays is a diagnosis and so much of it seems like normal child development/behavior? But I’m not an expert at all.

Anyways, my problem is my son is 2.5 and absolutely LOVES his daycare so some days when we pick him up he’s thrilled to see us but once he realizes he’s leaving the fun he throws a tantrum. Once we’re in the car though he’s totally fine. He doesn’t do this everywhere and he’s one of those kids when he’s tired he’s tough to reason with or explain things to. My main question was if there’s anything I can do to help with this transition to help minimize the meltdowns? I haven’t really heard this be a big sign of autism but let me know if I’m wrong? I did some research and he doesn’t have any other symptoms so I was just off put by that persons comment.

Appreciate any guidance, thank you